1 Setting up data

Data from Human Mortality Database and Human Fertility Database was used to calculate birth rates. This was tidied to give Under-18 rates:

Code Country Year rate GDPperCap MF_ratio MobilePhones UrbanPop
1 Austria 1985 8.63 9172.10 1.04 0.13 64.31
1 Austria 1986 8.44 13083.07 1.04 0.25 64.04
1 Austria 1987 8.19 16392.77 1.03 0.34 63.77
1 Austria 1988 7.89 17578.62 1.04 0.48 63.50
1 Austria 1989 8.58 17468.95 1.04 0.66 63.23
1 Austria 1990 8.80 21680.99 1.04 0.95 62.96

Abortion estimates were added to give Under-20 rates:

Code Country Year pRate rate GDPperCap MF_ratio MobilePhones UrbanPop
2 Czechia 1990 71.17 46.01 3917.16 1.05 0.00 75.22
2 Czechia 1991 72.91 47.52 2878.72 1.05 0.01 75.16
2 Czechia 1992 69.70 45.14 3352.03 1.05 0.04 75.03
2 Czechia 1993 62.31 42.91 3931.74 1.05 0.14 74.90
2 Czechia 1994 46.97 32.33 4601.95 1.04 0.29 74.77
2 Czechia 1995 36.53 24.43 5788.15 1.04 0.47 74.64

2 Iterating through year combinations

For each comparison, I iterated through all combinations of years as special predictors to minimise MSPE (whilst prioritising fewest groupings). For example, for the under-18 basic model with years as special predictors:

it_u18_rateSp <- testSynthIterations(
  yrs = 1985:1998,
  pred = "rate",
  data = synthData_u18[,1:4],
  ccodes = u_18_ccodes,
  n = 4,
  predictors = NULL,
  time.optimise = 1985:1998
) %>%
  arrange(groups, mspe)

3 Generating Synthetic Control models for all Under-18 comparisons

3.1 Model 1: Rate only as predictor

3.1.1 England vs Synthetic Control

3.1.2 Weights and balance

Country weights
Country Weight
Lithuania 0.648
Italy 0.179
Norway 0.105
United States of America 0.056
Poland 0.005
Czechia 0.001
Estonia 0.001
Finland 0.001
Germany 0.001
Portugal 0.001
Switzerland 0.001
Austria 0.000
Denmark 0.000
France 0.000
Hungary 0.000
Iceland 0.000
Netherlands 0.000
Northern Ireland 0.000
Scotland 0.000
Slovenia 0.000
Spain 0.000
Sweden 0.000
Predictor weights
v.weights
special.rate.1985.1987 0.071
special.rate.1988.1989 0.221
special.rate.1990.1992 0.615
special.rate.1993.1998 0.092
Predictor balance between synthetic and treated units
Treated Synthetic Sample Mean
special.rate.1985.1987 14.470 14.738 9.817
special.rate.1988.1989 15.675 15.537 9.670
special.rate.1990.1992 16.223 16.262 10.214
special.rate.1993.1998 16.176 16.066 8.646

3.1.3 Placebo testing by country and time

3.2 Model 2: GDP as predictor

3.2.1 England vs Synthetic Control

3.2.2 Weights and balance

Country weights
Country Weight
Sweden 0.836
United States of America 0.164
Austria 0.000
Czechia 0.000
Denmark 0.000
Finland 0.000
France 0.000
Germany 0.000
Hungary 0.000
Iceland 0.000
Italy 0.000
Lithuania 0.000
Netherlands 0.000
Norway 0.000
Poland 0.000
Portugal 0.000
Spain 0.000
Switzerland 0.000
Predictor weights
v.weights
GDPperCap 0
special.rate.1990 0
special.rate.1991.1992 0.45
special.rate.1993.1998 0.55
Predictor balance between synthetic and treated units
Treated Synthetic Sample Mean
GDPperCap 22161.231 13399.645 20840.131
special.rate.1990 16.386 16.780 9.297
special.rate.1991.1992 16.142 16.679 9.482
special.rate.1993.1998 16.176 15.753 7.908

3.2.3 Placebo testing by country and time

3.3 Model 3: All predictors

3.3.1 England vs Synthetic Control

3.3.2 Weights and balance

Country weights
Country Weight
Sweden 0.836
United States of America 0.164
Austria 0.000
Czechia 0.000
Denmark 0.000
Finland 0.000
France 0.000
Germany 0.000
Hungary 0.000
Iceland 0.000
Italy 0.000
Lithuania 0.000
Netherlands 0.000
Norway 0.000
Portugal 0.000
Spain 0.000
Switzerland 0.000
Predictor weights
v.weights
GDPperCap 0
MobilePhones 0
UrbanPop 0
MF_ratio 0
special.rate.1990 0.104
special.rate.1991.1992 0.364
special.rate.1993.1998 0.532
Predictor balance between synthetic and treated units
Treated Synthetic Sample Mean
GDPperCap 22161.231 13399.560 21881.386
MobilePhones 8.938 7.178 9.152
UrbanPop 78.302 54.795 73.382
MF_ratio 1.047 1.037 1.047
special.rate.1990 16.386 16.779 9.282
special.rate.1991.1992 16.142 16.678 9.480
special.rate.1993.1998 16.176 15.753 7.956

3.3.3 Placebo testing by country and time

4 Generating Synthetic Control models for all Under-20 comparisons

4.1 Model 4: England vs Synthetic Control

4.1.1 England vs Synthetic Control

4.1.2 Weights and balance

Country weights
Country Weight
Italy 0.723
United States of America 0.211
Netherlands 0.066
Czechia 0.000
Denmark 0.000
Estonia 0.000
Finland 0.000
France 0.000
Germany 0.000
Hungary 0.000
Iceland 0.000
Lithuania 0.000
New Zealand 0.000
Norway 0.000
Poland 0.000
Portugal 0.000
Scotland 0.000
Slovenia 0.000
Spain 0.000
Sweden 0.000
Switzerland 0.000
Predictor weights
v.weights
special.pRate.1990.1993 0.212
special.pRate.1994.1996 0.607
special.pRate.1997.1998 0.181
Predictor balance between synthetic and treated units
Treated Synthetic Sample Mean
special.pRate.1990.1993 63.425 63.771 40.784
special.pRate.1994.1996 60.200 60.781 34.130
special.pRate.1997.1998 63.850 60.938 31.983

4.1.3 Placebo testing by country and time

4.2 Model 5: GDP as predictor

4.2.1 England vs Synthetic Control

4.2.2 Weights and balance

Country weights
Country Weight
Lithuania 0.581
United States of America 0.419
Czechia 0.000
Denmark 0.000
Finland 0.000
France 0.000
Germany 0.000
Hungary 0.000
Iceland 0.000
Italy 0.000
Netherlands 0.000
New Zealand 0.000
Norway 0.000
Poland 0.000
Portugal 0.000
Spain 0.000
Sweden 0.000
Switzerland 0.000
Predictor weights
v.weights
GDPperCap 0
special.pRate.1990.1993 0.642
special.pRate.1994.1996 0
special.pRate.1997.1998 0.358
Predictor balance between synthetic and treated units
Treated Synthetic Sample Mean
GDPperCap 22161.231 27021.323 20232.166
special.pRate.1990.1993 63.425 65.364 36.353
special.pRate.1994.1996 60.200 58.607 30.740
special.pRate.1997.1998 63.850 59.852 29.007

4.2.3 Placebo testing by country and time

4.3 Model 6: All predictors

4.3.1 England vs Synthetic Control

4.3.2 Weights and balance

Country weights
Country Weight
Lithuania 0.581
United States of America 0.419
Czechia 0.000
Denmark 0.000
Finland 0.000
France 0.000
Germany 0.000
Hungary 0.000
Iceland 0.000
Italy 0.000
Netherlands 0.000
Norway 0.000
Portugal 0.000
Spain 0.000
Sweden 0.000
Switzerland 0.000
Predictor weights
v.weights
GDPperCap 0
MobilePhones 0
UrbanPop 0
MF_ratio 0.001
special.pRate.1990.1993 0.541
special.pRate.1994.1996 0.299
special.pRate.1997.1998 0.158
Predictor balance between synthetic and treated units
Treated Synthetic Sample Mean
GDPperCap 22161.231 27021.250 21631.593
MobilePhones 8.938 12.390 9.265
UrbanPop 78.302 85.333 74.102
MF_ratio 1.037 1.048 1.045
special.pRate.1990.1993 63.425 65.367 37.369
special.pRate.1994.1996 60.200 58.609 31.473
special.pRate.1997.1998 63.850 59.853 29.789

4.3.3 Placebo testing by country and time